another option to try: if you can enable keysteps soft thru in the software, you could:
dt midi out to
keystep midi in
keystep midi out (with soft thru)
to dn midi in
from dn midi thru to dt
this way you can send all midi stuff plus switch directly on the keystep, which unit to control… i did that some time ago with my a4 and ar and it worked with keystep…